1. Field
Embodiments of the document relate to a liquid crystal display capable of achieving uniform display quality using a source drive circuit having a plurality of output channels each having a different resistance.
2. Discussion of the Related Art
Active matrix type liquid crystal displays display a moving picture using a thin film transistor (TFT) as a switching element. The active matrix type liquid crystal displays have been implemented in televisions as well as display devices in portable devices, such as office equipment and computers, because of the thin profile of an active matrix type liquid crystal displays. Accordingly, cathode ray tubes (CRT) are being rapidly replaced by active matrix type liquid crystal displays.
A liquid crystal display generally includes a liquid crystal display panel, a backlight unit providing light to the liquid crystal display panel, source driver integrated circuits (ICs) supplying a data voltage to data lines of the liquid crystal display panel, gate driver ICs supplying a gate pulse (i.e., a scan pulse) to gate lines (i.e., scan lines) of the liquid crystal display panel, a control circuit controlling the source driver ICs and the gate driver ICs, a light source driving circuit driving a light source of the backlight unit, and the like.
In the liquid crystal display, the size of each source driver IC is much smaller than the size of a portion of a pixel array driven by each source driver IC. Further, a pitch between output channels of the source driver ICs is smaller than a pitch between the data lines. Because of this, as shown in FIG. 1, link lines LINK are formed between output channels of source driver ICs SIC and data lines of a pixel array PIXA to respectively connect the output channels of the source driver ICs SIC to the data lines. A length of the link lines LINK increases as a distance between the output channels of the source driver ICs SIC and the data lines increases. Accordingly, a resistance (hereinafter referred to as a “link resistance”) of the link line LINK increases as the link line LINK goes to both ends of the pixel array PIXA. According to an experimental result of resistance measurement, the link resistance may vary depending on the size and a resolution of the liquid crystal display panel. However, a difference between a minimum value and a maximum value of the link resistance may increase to several kΩ.
A voltage charge amount of liquid crystal cells of the pixel array PIXA varies depending on the link resistance. In other words, a voltage charge amount of the liquid crystal cell connected to the data line having a large link resistance is less than a voltage charge amount of the liquid crystal cell connected to the data line having a relatively small link resistance. The voltage charge amount of the liquid crystal cell is inversely proportional to the link resistance. As a result, because the voltage charge amount of the liquid crystal cell varies because of a deviation of the link resistances, it is difficult to display an image with uniform luminance throughout the pixel array.